The present invention relates to a method for determining the air entering the cylinders of an internal combustion engine having a supercharger.
German Patent No. 32 38 190 describes an xe2x80x9cElectronic System for Controlling or Regulating Performance Characteristics of an Internal Combustion Engine.xe2x80x9d Specifically, it describes a method of determining the pressure in the intake manifold on the basis of the rpm and the air flow rate in the intake manifold and conversely the air flow rate on the basis of the rpm and pressure. The method described therein makes use specifically of physical relationships prevailing in the air intake manifold with the goal of optimal control of the internal combustion engine.
International Patent Publication No. WO96/32579 describes a method of model-supported determination of the air entering the cylinders of an internal combustion engine. To do so, a physical model is crated, describing the relationships in the intake system of an internal combustion engine without a supercharger, using parameters representing the degree of opening of the throttle valve, the ambient pressure and the valve position as input quantities of the model. In addition, the instantaneous value determined for the air entering the cylinders of the internal combustion engine is used to predict future values.
The conventional system cannot be used with supercharged internal combustion engines, because additional physical factors must also be taken into account due to the supercharging.
Therefore, an object of the present invention is to provide a device for determining the air entering the cylinders of an internal combustion engine having a supercharger as a function of quantities such as rpm, air throughput in the intake manifold, throttle valve position values and temperature which comprehensively take into account the physical processes taking place in supercharged internal combustion engines.
With this device according to the present invention, it is possible to determine the physically correct or at least approximate relationships prevailing in the intake manifold of an internal combustion engine having a supercharger, and then to base the determination of the quantity of fuel accordingly.